Knitting machine cam system with pressing off means

ABSTRACT

In a flat knitting machine cam system for shaping or fashioning panels of the kind having a raising cam which brings needles up to clear their loops and subsequently take yarn for knitting, and a stitch cam for lowering raised needles, a cam track which allows butts to descend is provided subsequent to the raising cam but before the stitch cam, reckoned in the direction of relative movement of butts through the cam system, so that needles associated with butts which descend the track can be caused not to take yarn. The cam system also includes means for selectively guiding butts along the track.

United States Patent [1 1 Betts et al.

[ Nov. 4, 1975 KNITTING MACHINE CAM SYSTEM WITH PRESSING OFF MEANS [75] Inventors: Max Williams Betts, Coventry;

Frank Robinson, Borrowash, both of 21 Appl. No.: 328,381

[30] Foreign Application Priority Data 3,340,708 9/1967 Krause 66/75 3,614,877 10/1971 Radin 66/57 FOREIGN PATENTS OR APPLICATIONS 1,522,674 4/1968 France 66/78 608,051 1/1935 Germany 66/57 Primary Examiner--W. C. Reynolds Assistant Examiner-A. M. Falik Attorney, Agent, or Firm-Davis, Hoxie, Faithfull & l-lapgood ABSTRACT In a flat knitting machine cam system for shaping or fashioning panels of the kind having a raising cam which brings needles up to clear their loops and subsequently take yarn for knitting, and a stitch cam for lowering raised needles, a cam track which allows butts to descend is provided subsequent to the raising cam but before the stitch cam, reckoned in the direction of relative movement of butts through the cam system, so that needles associated with butts which descend the track can be caused not to take yarn. The cam system also includes means for selectively guiding butts along the track.

5 Claims, 6 Drawing Figures US. Patent Nov. 4, 1975 Sheet 1 of4 3,916,648

I JACK coumousn I US. Patent Nov. 4, 1975 Sheet 2 of4 3,916,648

US. Patent Nov. 4, 1975 Sheet4 0f4 3,916,648

KNITTING MACHINE CAM SYSTEM WITH PRESSING OFF MEANS This invention relates to a cam system for shaping or fashioning panels in a flat knitting machine, the cam system being of the kind comprising a raising cam which brings needles up to clear their loops and subsequently take yarn for knitting, and a stitch cam, for lowering raised needles.

The invention aims to provide a cam system of this kind in which the raising cam is also used to bring the needles up to clear for pressing off loops. Normally, a separate raising cam is used for this purpose but the presence of a separate raising cam increases the length of the cam box required to house the cam system. In a V-flat knitting machine this increases the time taken for the cam box to traverse the machine and thus reduces the rate at which fabric is produced. Increase in the length of the cam box can also be a disadvantage in a circular knitting machine, particularly one with a reciprocating or contra-rotating cam box action.

Accordingly, the invention consists in a knitting machine cam system of the kind referred to, in which a cam track allowing butts to descend is provided subsequent to the raising cam but before the stitch cam in the direction of relative movement of butts through the cam system, whereby needles associated with butts which descend the said track can be caused not to take yarn, the cam system including means for selectively guiding butts along the said track. Said last-named means may comprise, for example, selectively positionable jacks which can be positioned to contact a fixed lowering cam or to miss the lowering cam.

The means for guiding butts along the said track may comprise a further cam engageable with butts other than those which are to travel along the said track and located on the same elements as the first mentioned butts or on elements associated with the elements carrying the first mentioned butts, the said other butts being selectively raisable for engagement with the said cam.

The said means may alternatively comprise a further cam engageable with the butts which are to travel along the said track, when the butts are raised to a sufficient extent in relation to the needle bed, the machine including a device for selectively raising the said butts to that extent.

The said means may, as a further alternative, comprise a picker device adapted to contact a butt which is to travel along the said track or to contact a butt other than one which is to travel along the said track, the said other butt being located on the same element as the butt which is to travel along the said track or on a different element.

The invention will be further described, by way of example, with reference to the accompanying drawings in which:

FIGS. 1, 2 and 3 are diagrams illustrating parts of three cam systems according to the invention,

FIG. 4 is a diagram illustrating the needle and jack for use in conjunction with the cam system of FIG. 1,

FIG. 5 is a section on the line VV of FIG. 2, and

FIG. 6 is a perspective view of the cam system shown in FIG. 2.

The cam system shown in FIG. 1 includes a raising cam 5 and a stitch cam 6 for cooperation with butts on needles of a knitting machine. In showing the cams of the invention, the normal basic construction of a cam system has been used in which the upper part of a raising cam is in one piece and the lower part, which serves to raise butts to tuck height, is in a separate unitary piece. A groove is then milled in the block constituting the upper part of the raising cam and the edge of this groove appears at the top and bottom of the block. The raising cam 5 raises the needles, in two stages, to a height at which they clear that is to a height at which a loop of yarn held in the hook moves down over the latch onto the shank of the needles below the latch. In the operation of the system of FIG. 1 in the foregoing orientation, a retracted jack butt 13 (dotted line showing of FIG. 4) would be too low to contact the cam 14 and would miss it, thereby failing to divert needle butt 10 down the track 8. A liftedbutt 13 (full line showing of FIG. 4) would be high enough to contact cam 14 and would move along it, thereby diverting needle butt 10 down track 8.

In the operation of the system of FIG. 2, the needle 9 would not have a butt 10 and the butt 13 of jack 1] would interact with the cams of FIG. 2. A fully lifted butt 13 (full line showing of FIG. 4) would be high enough to contact the cam 23, thereby diverting itself down the track 22 and causing downward movement of the associated needle 9. A fully retracted butt l3 (dotted line showing of FIG. 4).would miss the cam 23 and not be diverted.

When a needle which has been raised to clear height is subsequently lowered, it will press off its loop unless .yarn is supplied to the hook, in which case a further loop will be drawn and knitting will take place.

Before the stitch cam 6 is a guard cam with a dwell portion 7 at a height suitable for holding needles while yarn is presented to their hooks. Subsequent to the raising cam 5 but before the stitch cam 6 in the direction of relative movement of the needles through the cam system (in the direction of the arrow A in FIG. 1) is located a cam track 8 allowing needle butts by the raising cam 5 to descend before they reach the stitch cam 6, that is before they reach the cam portion 7 where the needle hooks take yarn. Thus the needles associated with butts travelling along the track 8 will not take yarn. I

Each needle 9 (FIG. 4) has a butt 10 for cooperation with the raising cam 5 and stitch cam 6 and with the cam track 8. Associated with each needle 9 is a further element constituted by a jack 11 joined to the needle by a linkage 12 allowing pivoting movement between the needle 9 and the jack 11. Each jack 11 carries a butt 13. V I

The floor of the tricks in which the needles 9 and jacks 11 slide, is arranged, in known manner, to allow pivoting movement of the jacks between the position shown in broken lines in FIG. 4 and the lifted position shown in full lines in that Figure. Known means such as an electro-magnetically operated jack controller (shown in FIG. 4) connected with the jack is incorporated in the knitting machine for effecting movement of the jack to whichever position is desired. Such mechanisms are already incorporated in knitting machines to enable needles to be programmed to effect stitch transfer or to carry out other operations as required for patterning.

The cam system of FIG. 1 further includes a cam 14 for cooperation with the butts 13 of the jacks 11. A butt 13 will engage the cam 14 only when the jack 11 on which it is carried is located in the position shown in full lines in FIG. 4. The jack 11 will then be brought down, as the jack and its associated needle 9 move relative to the cam system so that the butt 10 of the associated needle 9 enters the track 8 and the needle descen'ds without taking yarn.

Thus, by means of the mechanism for selectively pivoting jacks 11 to either of the positions shown in FIG.

4, needles can be selected for casting off loops or for knitting.

In a cam box for a V-flat knitting machine using double system knitting, further cams comprising a mirror image of those shown in FIG. 1 will be included to provide for casting off when the cam box traverses the needle beds in a direction such that the relative movement of the needles through the cam box is in the opposite direction to the arrow A, FIG. 1. In a machine using single system knitting, a single press-off track 8 will normally be sufficient, but a corresponding track for the opposite direction of cam box movement may be provided.

The cam system illustrated in FIGS. 2, 5 and 6 includes a two part raising cam 17, a stitch cam 18 and a guard cam with a dwell portion 19 where the needles take yarn for knitting. Subsequent to the raising cam 17 but before the stitch cam 18 in the direction of relative movement of the needles through the cam system (arrow B) is located a cam track 22 allowing butts to descend before they reach the stitch cam 18, that is before they take yarn for knitting.

A cam 23 is located adjacent the entry 24 to the cam track 22 and is of a height such that it will contact only lifted butts. The needles and jacks used in conjunction with the cams of FIG. 2 are similar to those shown in FIG. 4 except that the needles 9 do not carry butts 10, the butts 13 of the jacks 11 serving to cooperate with the raising cam 17 and stitch cam 18 to effect the needle movements.

When a butt 13 is lifted that is, pushed into the cam tracks by moving the associated jack 11 to the position shown in full lines in FIG. 4, the butt 13 will engage the cam 23 as the cam system moves past the associated needle 9 and jack 11 and the butt will be directed down the cam track 22 without taking yarn. The loop on the associated needle 9 will thus be pressed off. Jacks not lifted will have their butts completely miss the cams, that is, they will not contact the stitch, press-off or raising cams. However, jacks can also be partially lifted enough for their butts to contact the raising and stitch cams, but not lifted far enough for their butts to contact press-off cam 23.

In a cam box for a V-bed knitting machine using double system knitting a cam system which is a mirror image of that shown in FIG. 2 will be included together with the cam system of FIG. 2 so that provision is made for pressing off in both directions of travel of the cam box.

The cam system shown in FIG. 3 comprises a two part raising cam 27, a stitch cam 28 and a guard cam with a dwell portion 29 where needles take yarn for knitting. An escape track 30 is located subsequent to the raising cam 27 but before the stitch cam 28 in the direction of relative movement of the butts through the cam system (arrow C). The butts directed into the cam track 30 bring the associated needles down to a level at which the loops on the needles are pressed off. The descent of the needles, the butts associated with which enter the track 30, takes place before the needles have taken yarn to knit.

A needle and jack combination as shown in FIG. 4 is used in conjunction with the cam system of FIG. 3. A selecting means for bringing about pivotal movement of the jacks 11 is not required to select needles to descend by the cam track 30 since another device, as described below, is provided for this purpose. Such selecting means may, however, be required to control other operations in the running of the knitting machine. The butts 13 of the jacks ll cooperate with the raising cam 27 and the stitch cam 28 to cause the operating movements of the needles. The butts 13 are directed into the track 30 by meansof a conventional picker device 33 which acts on the butts 10 of the needles 9. If the head 35 of the picker device '33 is set as shown in FIG. 3, the first needle butt 10 of a group of needles 9 will strike the surface 36 on the head and will be deflected downwards pushing down the associated needle 9 and jack 11 so that the butt 13- on the jack moves into the cam track 30. The picker head 35 will be rotated about the axis 37 by the action of the needle butt 10 and will thereby be rendered inoperative so that the remaining needles of the group will pass through the cam system without being deflected downwards. The picker head is reset by rotating it to the position shown in FIG. 3 once more; the picker device 33 includes conventional means for carrying out this operation when desired.

Again, a cam box for a double system V-bed machine includes a cam system as shown in FIG. 3 together with its mirror-image.

In all three cam systems shown in the drawings, provision is made for raising needles only to tuck height by means of the two-part raising cam 5, 17 or 27 the upper part of which can be retracted. If the upper part of the raising cam of FIGS. 2 or 3 is only partly retracted, only lifted butts will engage the upper part of the raising cam and be pushed upwards to clearing height. These lifted.

butts may then be deflected down the escape track 22 or 30 to press off their loops.

Alternatively, in the cam system of FIG. 2, if the mechanism for positioning the jacks ll is capable of adjusting each jack to any one of three positions, then partly lifted butts can be arranged to engage the partly retracted upper part of the raising cam together with fully lifted butts whereas only fully lifted butts will engage the cam 23 and be deflected down the track 22 to press off.

The part of each raising cam surrounding the entry portion of the escape track 8, 22 or 30 is recessed to reduce the risk of a butt being partly deflected into the entry so as to foul the edge of the track.

What is claimed is:

1. A cam system for a flat knitting machine having independently operable needles, said cam system comprising a. a raising cam for contacting butts associated with needles of said machine to raise said butts and needles so that the needles clear yarn loops held thereon and take yarn for knitting,

b. a stitch cam for contacting raised butts to lower the associated needles after they have taken yarn and cause them to knit,

c. a cam track between said raising cam and said stitch cam for said butts to descend before the associated needles take yarn, and

d. directing means separate from said cam track for lowering selected needles raised to clearing height by said raising cam and routing the associated butts into said cam track.

2. The cam system claimed in claim 1 wherein said directing means comprises:

a. a jack element associated with each needle and carrying said butt,

b. means for lifting and retracting selected jack elements in relation to the needle bed of the knitting machine,

0. a further cam engageable with butts of lifted jack elements, said further cam being arranged to direct said butts of lifted jack elements into said cam track.

I 3. The cam system claimed in claim 1 wherein said directing means comprises a further cam and a second group of butts different from the butts first referred to, each butt of said second group also being associated with a needle of the machine, said further cam being engageable with said second group of butts when the latter are lifted in relation to the needle bed.

4. The cam system claimed in claim 1 wherein said directing means comprises a picker device.

5. A cam system for a flat knitting machine having independently operable needles located in at least one needle bed and means for supplying yarn to said needles, said cam system comprising:

a. structure defining a raising cam for contacting butts associated with the needles of said machine to raise said butts and needles to a height such that the needles clear yarn loops held thereon and take yarn from said supply means for knitting,

b. a stitch cam for contacting raised butts to lower the associated needles after they have taken yarn and cause them to knit,

c. a cam track formed in said raising cam structure at a position in advance of that at which said raised needles take yarn in their movement through the cam system, said cam track providing a path for butts to descend without the associated needles taking yarn, and

d. directing means separate from said cam track for lowering selected needles raised to clearing height by said raising cam and for routing the associated butts into said cam track.

UNITED STATES PATENT OFFICE CETEMCATE ()F CORRECTION PATENT NO. 3 ,916,648 DATED November 4 1975 INVENTOR(S) Z MAX WILLIAM BETTS and FRANK ROBINSON It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, the first inventor's middle name should be changed from "Williams" to -Wi11iam-.

fii'gncd and Sealed this twentieth Day of April1976 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer (mnmissiuncr uflarenrs and Trademarks 

1. A cam system for a flat knitting machine having independently operable needles, said cam system comprising a. a raising cam for contacting butts associated with needles of said machine to raise said butts and needles so that the needles clear yarn loops held thereon and take yarn for knitting, b. a stitch cam for contacting raised butts to lower the associated needles after they have taken yarn and cause them to knit, c. a cam track between said raising cam and said stitch cam for said butts to descend before the associated needles take yarn, and d. directing means separate from said cam track for lowering selected needles raised to clearing height by said raising cam and routing the associated butts into said cam track.
 2. The cam system claimed in claim 1 wherein said directing means comprises: a. a jack element associated with each needle and carrying said butt, b. means for lifting and retracting selected jack elements in relation to the needle bed of the knitting machine, c. a further cam engageable with butts of lifted jack elements, said further cam being arranged to direct said butts of lifted jack elements into said cam track.
 3. The cam system claimed in claim 1 wherein said directing means comprises a further cam and a second group of butts different from the butts first referred to, each butt of said second group also being associated with a needle of the machine, said further cam being engageable with said second group of butts when the latter are lifted in relation to the needle bed.
 4. The cam system claimed in claim 1 wherein said directing means comprises a picker device.
 5. A cam system for a flat knitting machine having independently operable needles located in at least one needle bed and means for supplyinG yarn to said needles, said cam system comprising: a. structure defining a raising cam for contacting butts associated with the needles of said machine to raise said butts and needles to a height such that the needles clear yarn loops held thereon and take yarn from said supply means for knitting, b. a stitch cam for contacting raised butts to lower the associated needles after they have taken yarn and cause them to knit, c. a cam track formed in said raising cam structure at a position in advance of that at which said raised needles take yarn in their movement through the cam system, said cam track providing a path for butts to descend without the associated needles taking yarn, and d. directing means separate from said cam track for lowering selected needles raised to clearing height by said raising cam and for routing the associated butts into said cam track. 